The present application concerns tubes, such as a tubular automotive front bumper beam or door beam, or a tubular bracket for furniture, and more particularly concerns a tube having an insert positioned within the tube to prevent premature collapse upon experiencing impact or high bending stress.
Tubular bumpers have received wide acceptance in the automotive market based on their high strength-to-weight ratio. However, further improvements are desired to stabilize predetermined areas on certain wall sections of tubular bumper beams for improved impact strength. For example, it is desirable in some bumper beam designs to better stabilize the front and rear wall sections near ends of the bumper beam where added strength is desired to withstand corner impacts. Also, added stability may be desired on the rear wall in the area of the frame-to-bumper mounts.
Some tubular bumper constructions have walls that are stabilized by addition of foam or other polymeric inserts located inside or outside the tubular bumpers. However, this can add an undesirable amount of cost and weight to the bumpers. Other bumper constructions have welded brackets and braces attached to the tubular bumpers. However, this can add cost and weight, as well as complexity to the assembly (including additional parts and pieces), quality problems, added secondary processes, additional inventory, fixturing problems, etc.
Accordingly, a tubular assembly solving the aforementioned problems and having the aforementioned advantages is desired, as well as the associated methods and apparatus.
In one aspect of the present invention, an article includes a tubular beam having a front wall and a rear wall that define a cavity, a tubular insert located in the cavity, and having front and rear ends adjacent the front and rear walls, respectively. The front wall has an integrally formed first extruded flange extending into the front end of the tubular insert, and the rear wall has an integrally formed second extruded flange extending into the rear end of the tubular insert. The first and second extruded flanges hold the tubular insert in place.
In another aspect of the present invention, a vehicle bumper construction includes a tubular beam of high strength material suitable for use as a vehicle bumper beam. The tubular beam has front, rear, top and bottom walls, and further has vehicle mounts for mounting the beam to a vehicle frame, with at least one of the walls having contiguous insert-retaining material. A wall-reinforcing insert has a cavity aligned with the insert-retaining material, and a retainer is integrally formed from the insert-retaining material of the one wall by deformed portions of the material that extend telescopingly inwardly into the cavity and into the insert to thus retain the insert in the tubular beam.
In another aspect of the present invention, a method comprises steps of providing a tubular beam having a front wall and a rear wall that define a cavity, and locating a tubular insert in the cavity with front and rear ends located adjacent the front and rear walls, respectively. The method further includes integrally forming a first extruded flange from the front wall including extending a tubular portion of the first extruded flange into the front end of the tubular insert, and further includes integrally forming a second extruded flange from the rear wall including extending a tubular portion of the second extruded flange into the rear end of the tubular insert, such that the first and second extruded flanges hold the tubular insert in place.
In yet another aspect of the present invention, a method comprises steps of providing a tubular beam made of high strength material adapted for use as a vehicle bumper beam, the tubular beam having front, rear, top and bottom walls, and including end sections and vehicle mounts located inboard of the end sections. The method further includes providing wall-reinforcing tubular inserts having a cavity, and placing the inserts transversely in the end sections of the tubular beam. The method still further includes forming a retainer from integral and continuous material in at least one of the walls in the end sections by telescopingly deforming the material of the one wall inwardly into the cavity to thus provide a main retention of the insert in the tubular beam.
These and other features, advantages, and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings.